Hi DGO,
I'm sorry to hear that you are struggling at the moment. I think a thing to remember about Hba1c, is that it only tells us so much- as you have demonstrated by your post. On paper a Hba1c of 6 sounds great, but in fact if your diabetes control is difficult for you and you are clearly trying very hard with all your blood testing and injections but not getting the results you want, then it sounds like you could do with some help and support.
Is this swinging from high to low a recent/new thing? Are you quite confident in your carb counting?
In terms of losing hypo awareness, I have also experienced this, it can be very frightening. However, with help from my diabetes team, having less extremes in blood sugar levels swinging from high to low and vice versa has increasingly brought back my awareness. I hope this may reassure you a bit.
You may be aware of all this, but I find if I give a correction dose on it's own, it seems to have a more dramatic effect on bringing my sugars down. This may be something to bear in mind as to why you are dropping low. Also being aware that the rapid insulin will be active for about 3-4 hours after you inject, so trying to avoid a 'stacking-up' effect by not doing too many corrections and allowing the insulin already in your system to do its work may prevent further lows.
I don't know if any of this is of use to you, but I really hope that if you explain to your diabetes team that although you have an excellent Hba1c level, you are struggling, that they will be able to help.
I understand how tiring it can be when you are trying so hard to get good control day after day and I really hope things get a bit easier for you.